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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
    var arr=[
        [1,2,3,4,5],
        [1,2,3,4,5],
        [1,2,3,4,5],
        [1,2,3,4,5],
        [1,2,3,4,5]
    ]
    var res = 0;
    for(var i = 0 ; i < 5 ; i++){
        for(var j = 0 ; j <= i ; j++){
            res += arr[i][j]
        }
    }
    console.log(res);


</script>
</body>
</html>